Stellpflug, a retired cancer nutritionist with a pastoral career who now teaches Bible study and Sunday school at Sunrise Baptist Church in Custer, Washington, told The Christian Post in an interview that he received an email response from Twitter on July 3 telling him that his tweet "has not been approved for use in your Twitter Ads campaign."

The tweet in question states: "One Man One Woman is about God's original design for marriage carried from Adam and Eve in the garden through today." The tweet also includes a photo of the book and a link to the WestBow Press online bookstore.

The July 3 email that Twitter sent to Stellpflug, which was shared with The Christian Post, explained that the tweet violated Twitter's ad policy.

"This determination is based on the following Twitter Ads policy: Hate," Twitter's email to the pastor reads.

The email included a link to a webpage outlining Twitter's ad policy, which states that Twitter prohibits "hate content, sensitive topics, and violence globally."

Twitter lists a number of scenarios in which the policy applies, including "hate speech or advocacy against an individual, organization or protected group based on race, ethnicity, national origin, color, religion, disability, age, sex, sexual orientation, gender identity, veteran status or other protected status."

"They started promoting it, they took my money," Stellpflug told The Christian Post. "Then, I get that email that tweet was not approved and that it was determined to be hate."

Stellpflug assured that his book is "definitely not an anti-gay book" and that it is "not about lesbian, gay bisexual and transexual movement."

"In fact, I address different issues — homosexuality, adultery, divorce, pornography and other like issues," he said. "I don't give any special weight to homosexuality. I do give tremendous weight to God's forgiveness, God's judgment versus our judgment."

The Christian Post reached out to Twitter for comment on why Stellpflug's tweet was considered to be "hate." No response was received before press time.

"I suppose if I named my book 'One Man and Another Man Together in Marriage,' it would soar past the critics and actually garner praise as some clarion call for peace and unity," Stellpflug told CP.

"My book is not hate! It highlights conservative Christian marriage values — therefore it is 'hate.' Have we stooped so low in our country that my freedom of speech is squelched because I promote my Christian beliefs? I'll tell you where the hate is. It is flaunted against the majority by the few as a tool to promote liberal agendas."

Another topic the book touches on is the use of everyday chemicals that cause hormone disruption. Stellpflug argues that use of such chemicals is causing a "hormonal evolution."

"The fact is we are helping cause the hormonal evolution of our species at breakneck speed because of the everyday use of powerful hormone disruptors," the book states. "Add to this the societal shift of acceptance and even an encouragement toward homosexual exploration and the simple hormonal evolution expands to include sexual revolution."

Stellpflug admitted that he recounts in his book a time when he pulled a gun on his gay college roommate and nearly shot him. Stellpflug accused the 30-year-old roommate of making a "homosexual pass" at him while he was asleep.

"In that story, I did pull a gun on him," Stellpflug said. "But it wasn't out of [anti-LGBT] hate, it was, 'Touch me again and I will kill you.' That is exactly what I said to the man."

Stellpflug told CP that on Thursday he pinned another tweet promoting his book and paid Twitter to promote it. Stellpflug did not receive a response to his latest advertising campaign from Twitter administrators before press time.

This is not the first time that Twitter has been accused of rejecting an ad campaign promoting a social conservative value. In June, it was reported that Twitter is not allowing pro-life organizations like Live Action and the Susan B. Anthony List to procure ads that warn against abortion, show unborn baby ultrasounds and fact-check claims from the nation's largest abortion provider, Planned Parenthood.